Can anyone recommend a kit for testing pressure/temperature of my loops? Also is it difficult to top up the lines ? Im no HVAC contractor so thought i'd ask before trying to do it. I had someone come out to test the lines/temp. The pressure was a bit low and he was supposed to come by and top it up. Now I beleive this person got sick and now disappeared (he was pretty old). I don't want to have to pay again for another diagnostic by someone else to get it topped up. If its pretty easy then I'd like to buy what I need and do it myself. The unit is a Climatemaster 27 which P/T plugs. Thanks.